Truing mechanism for grinding wheels



@ct 26,1931. w. LE BRYANT 1,827,967

TRUING MECHANISM FOR GRINDINQ WHEELS Original Filed July 20, 1921 6Sheets-Sheet 1 Oct. 20, 1931. w BRYANT 1,827,967

TRUING MECHANISM FOR GRINDING WHEELS Original Filed July 20, 1921 6Sheets-Sheet 5 Oct. 20, 1931. w. LE R. BRYANT v TRUING MECHANISM FORGRINDING WHEELS Original Filed July 20, 1921 6 Sheets-Sheet yflganl 422%. I

Oct. 20, 1931. w. LE R. BRYANT "TRUING MECHANISM FOR GRINDING WHEELSOriginal Filed July 20, 1921 6 Sheets-Sheet 5 NNM MMN NMN .Oct. 20,1931f. w LE R BRYANT 1,827,967

" TRUING MECHANISM'FOR GRINDING WHEELS Origifial Filed July 20, 1 21aspeets-sfieet .6

Patented Oct. 20, 1931 man STATES PATENT OFFICE 1 WILLIAM LE ROY BRYANT,OF SPRINGFIELD, VERMONT; BLANCHE B. BRYANT, OE SPRINGFIELD, VERMONT,ADMINISTRATRIX F SAID WILLIAM LE ROY BRYANT,

nncnen TRUING MECHANISM FOR GRINDING- original applicatlon filed July20, 1921, Serial No. 486,080. Divided and this application fllcdDecember 26, 1925. Serial No. 77,837.

This application is a division of my. a pli-v cation entitled Grindingmachine, erial No. 486,080, filed July 20, 1921, upon which LettersPatent No. 1,575,968 were granted March 9, 1926. The invention relatesto improved mechanism for truing grinding .wheels which may be used inconjunction with the grinding machine described in the above mentionedapplication, and in which a has hitherto been possible. An object of theinvention is to provide for a relative reciprocation and transverse feedof the truing mechanism of the grinding wheel, in which one of theinstrumentalities is mounted to move toward the other about a fixedcenter. Other objects of the invention are to provide template orcontrol bars which are interchangeable and adjustable so that the accuaorate truing of the wheels is not dependent upon the skill of theoperator; and to providefor accurate truing of grinding wheels ofdifierent shapes, including those wheelswhich have portions which varyin diameter. In the drawings,-

ing machine such as is described in detail in my above mentioned LettersPatent. No. 1,575,968, and in which may improved truing mechanism isincorporate Fig. 2 is a fragmentary end elevation of the upper portionof the grinding machine, which includes the truing mechan sm;

Fig. 3 is similar to Fig. 2 but shows the opposite end; p

Fi t represents a section through the grin ing wheel on a verticalplanetransverseto the machine, and illustrates the truing mechanism inoperating position;

Fig. 5 illustrates a template or control bar for the truing mechanism,and the mechanism by which said control bar is adjustably and removablysupported;

Fig. 6 illustrates in perspective "and on an 99 of Fig.5;

better and more stable control is eflected than V Fig. 1 represents infront elevation a grindenlarged scale a'portion o'f the bar shownin Fig.10 re resents a vertical transverse section on the line 10-1O of Fig. 1;

Figs. 11 and 11 together represent a longitudinal section on the line1111 of Fig. 10, all on a larger scale;

Fig. 12 is a section onthe line 12--1'2 of Figure 11;

Figs. 13 to 16 inclusive represent diiferent of the invention as definedin the claims, that the phraseology hereinemployed is for the purpose ofdescription and not of limitation, and that the drawings are more orless conventional.

. Proceeding to adescription of the illustrated machine,'50 illustratesa hollow bed having suitable front, rear and end walls. On

the upper face or table formed by the bed there are two upright endstandards 51, 52,

which at their upper ends support two parallel bars 53, 54, one of whichsup orts a truing mechanism and the other 0 which.

sup rts the work-holding and rotating' erably the arms 55, 56 are castin hollow form Y for the sake of lightness, and they are clamped.

to the bar 54. The upper ortions of the arms may -be split-and provi edwith clamping screws 59'. Asa result of this construction, thew'orkcarrier, by loosening the clamp screws59, may'beadjusted longitudinallyof the bar 54" and then clamped 'rlag'idly thereto, so'that, by movingthe bar-.axi ly, the work carrier may be moved therewith. By mechanism,which I shall subsequently explain, the

bar may be moved manna 1y or automatically in an axial direction for thepurpose of ef-.

tapered bushings 60, 61, in which the bar 54' is journaled and in whichit may be moved longitudinally. These tapered bushings may be adjustedto compensate for wear by nuts 62, 63, abutting against the inner facesof the uprights. By mechanism, subsequently to be explained, the workcarrier and its supporting bar 54 may be swung about the axis of the bar54 for the purpose of advancing the work .to and withdrawing it fromthegrinding wheel.

The grinding wheel may be of any desired shape according to the work tobe ground. In the form shown in Fig. 14, it comprises three abradinmembers 91, 92 and 93, which may be of di erent' kinds of grindingmaterial, if desired. These may be provided with spacing and clampingmembers of any convenient type to secure them to a shaft for rotation.

Although a driving pulley may be mounted directly on the shaft 65 todrive the grinding wheel, I prefer to avoid the resulting bendingstresses on the shaft due to the lateral pull of the belt on a pulley,which stresses cause morerapid wear on the shaft bearings. A shaft 115is therefore mounted coaxially with the shaft 65 and is connectedthereto-by a suitable universal joint as shown and described in LettersPatent No. 1,575,968. A pulley 114 is mounted on the shaft 115 anddriven from any suitable source of power, as by a belt 113.

The grinding wheel is also preferably mounted in such a way that it canbe adjusted with its carrier 66 towards or from the work By inspectionof Figure 10, it will be observed that the work carrier depends normallyfrom the bar 54 in front of the grinding 'wheel. The movement of thework, which is carried by the work carrier, is in a curvilinear pathtowards or from the grinding wheel,

. swung 9. out its axisto efi'ect a feeding move:

iment of the work towards the grinding wheel or its withdrawal fromgrinding position.

parallel to the axis;

carrier, as by rotation of an abutment screw 5 68 The work carrier maybe reciprocated lon gitudinally of the work axis, and thus lonitudi-nally of the bar54 whose axis is paral el to that of the workaxis, so s to effect an axial movement of the work while it is inengagement' with the grinding wheel. In some cases, however, it is notdesirable to have this Fig. 11*, is provided with rack teeth 162 whichextend part way around its periphery. With the rack thus formed, thereis engaged a pinion 163 secured on a shaft 164 journaled in a block 165into which, the-end of timber 54 projects. The end of the shaft 164 isangular 1n cross section, as shown at 166 in Fig. 3, so that, byapplying a wrench or handle thereto, the pinion 163 may be rotated inone direction or the other to move the bar 54 longitudina-lly ofitsaxis, the blockin the meantime being held a ainst movement. I alsoprovide means by w ich the block itself may be rocked or reciprocatedback and forth to effect the automatic longitudinal reciprocation of thework carrier. To accomplish this result, an arm or lever 167 ispivotedon a pintle 168 mounted in lugs 169 projecting from the upright 52of-the' frame. This lever or arm 167 is rovided with an upwardlyprojecting yoke 1 0 which embraces a pin 171 inserted in the block 165and located almost directly above the pintle 168. Consequently, byrocking the lever 167 about the axis of the pivot or pintle 168, theblock 165 and the bar 54 may be reciprocated. The lever 167 isautomatically oscillated about its axis by any suitable mechanism drivenfrom the main power shaft. As described in Letters Patent,

No. 1,575,968, such mechanism is preferably provided with a clutchdevice such that when the operating handle is'operated to disengage theclutch, the latter will remain-in engagement until the work carrierreaches the right hand end of its movement as viewed in Fig. 1. This isdesirable particularly when shouldered work is being ground as thelarger grinding wheels are to the right of one facing the machine. Itisfurthermore desirable because, as will be subsequently explained, thework carrier carries the control template or bar which governs theaction of the truing mechanism on the wheel, and it is also desirablethat the work carrier should be stopped always at the same point intruing the wheel for any particular grinding operation.

For efiecting a relative transverse feed of the work and the grindingwheel, I employ a single speed automatic feed mechanism by Y which thework and the grinding wheel are I brought into grinding relation andcontinued in that relation until the Work has been reduced to thedesired diameter, after which the work and the tool are separated,whereupon the feed is automatically discontinued. Provision is made,however, by which the operator may manually effect a feeding orwithdrawing movement of the movable element. The transverse feedingmechanisms act through a slide 198 which is mounted on the bed of themachine and against an end of which rests a guide bar or template 197mounted on a dependent portion 196 of the longitudinal member 57 ofthework carrier. Since the work carrier is pivotally swung on an axis, theslide 198 acts as an adjustable stop to limit the outward swin ofthework carrier away from the grinding wheel.

For the reciprocation of certain parts of the machine, such as thesliding shaft 228,

fluid-actuated pistons maybe provided whichcan be readily controlled bsuitable valves.

Any suitable source of flui pressure may be used. With my grindingmachine I have provided a pressure system comprising a reser-.

voir 240 for fluid, and a rotary pump, the casing of which is indicatedat 242, from which conduits are led'to the various pistons and controlvalves. vided to prevent excessive pressure in the supply conduits."Thi's'pressure system as well as the other parts of the machine, whichhave been mentioned are fully described in Letters Patent No. 1,575,968,previously referred to.

The present invention involves one of the salient features of thegrinding machine, that is, the truing mechanism for the grinding wheels.The dressing tool is mounted in a swinging arm which is normally ininactive position but which may be swung downwardy so as to bring thedressing tool into operative relation to the grinding wheel. The

dressin tool is indicated at 300 and it is adjustablyclamped in aswinging arm 301,

the hub 302 of which is rigidly secured to the p bar 53, to whichreference has previously been made. This bar is'adaptedto oscillate inbushin s 303, 304,'placed in hearings in the uprig t standards 51, 52,and is also I adapted to slide therein. To protect the bearings,thevvbar 53 is provided with two sets of telescoping sleeves, 305, 306.In each case, the sleeve 306 is screwed into the thread-' ed a erture inthe upri ht or standard, and

the s eeve 305 can slide ack and forth with the bar 53. At one end, thebar 53.has a weighted arm 307 keyed thereto,'and between the hub of thisarm and a shoulder 308 on the bar there is placed a second Weightedlever 309. The hubs of these two levers have spaced shoulders 310, 311,adapted to engage I 'when'onehas moved to a limlted extent relatively tothe other. Normally, when the dressing tool is not in operation, theweighted Belief valves are also pro- -forms a arms 307, 309 hangdownwardly and hold wardly and upwardly until it reaches the positionshown in Fig. 4, in which position the dressing tool is engaged with thegrinding wheel. The bar 53 may now be reciprocated under the control ofthe operator. Any suitable mechanism for effecting its reciprocationis-employed, but preferably, inasmuch as I employ other mechanism whichis controlled by fluid pressure, I also utilize.

this pressure for moving the dressing tool bar. To this end, a casing312 is screwed to the hearing at the upper end of the upright- 52. Theend of the bar 53 is enlarged to form a cylinder 313, the inner end ofwhich may be closed by a plug 314. A stationary piston 315 is located inthe cylinder thus provided and a stationary extension or piston rod 316extends through a stufiing box located i-n'the head 317 at the end ofthe cylinderr The outer end of this piston rod is screwed into the endof the casing 312. Conduits 318, 319 extend through the piston rod, theformer connecting with the lefthand end of the cylinder and the latterconnecting with ther-ighthand end of the cylinder, as best shown in Fig.11.-- When the fluid is delivered through the conduit 318, the pistonbeing stationary, the entire bar 53 is moved to the left, and, ofcourse, when fluid is delivered through the conduit 319, the bar 53 ismoved to the right so that the dressing tool may be caused to traversethe face ofjthe grinding wheel. Suitable pipes-320, 321 connect, theconduits 318,1 319, respectively, with a valve mechanism contained inthe casing 326 and fully described .in Letters Patent No.

1,575,968. 'A handle3a 0 is attached to the valve, by manipulation ofwhich the operator may move the valve in one direction or the other tocause the corresponding movement of the bar 53 and the dressing toolcarried thereby. I

When the truing tool is operating on the grinding wheel, it may beguided in any desired path b the use of a control bar or template whichis preferably supported on the work carrier. Referring now to Figures4to 8, and 10, it will be noted that, on the front side of thelongitudinal bar 57 which ortio n of the work carrier, there is an uprigt longitudinal flange 350, and in the angle formed Jay this flange thereare secured two blocks 351, 352, which constitute portions of afholdingmechanism for the control bar or template. In these blocks there arearranged two center pins 353, 354. The block or holder 351 is split" sothat the center pin 353 may be clamped in place by the screw 355 afterthe center pin has been ad usted to proper position. The center pin 354is seated in a socket in the holder 352,

which is also split (as shown in Fig. 7) so that the split portions maybe drawn to ather by a screw 356 to clamp the center pin. K spring 357is seated in the socket and bears against the shoulder on the centerpin,-

as best shown in Fig. 5. By slightly loosenplaced in the holders andlocked rigidly in place-so as to guide the dressing tool arm as it isreciprocated axially of the bar 53. The control bar may be straight,shouldered, convexly or concavely curved, or tapered, as may be desired.Preferably, although not necessarily, it is circular in cross section. Ihave T shown in Fig. 5 a control bar which is indicated at 359 and whichhas centering recesses 360, 361 at its endsto receive the center pins353, 354. The ends of the control bar rest onflat faces v362, 362 (shownin -plan view in Fig. 5) on which the center pin holders351, 352 aresecured, and the'sides of the end portions of the control bar restagainst abutment. screws 363, 364, which are passed through theflange350 of the work carrier. The abutment screw 363 has a relatively coarsethread and it is locked in position by a set screw 365. The screw 364has a fine thread and is screwed into a threaded sleeve 366 inserted ina flange 350. The end of this screw has a knurled head 367 by which ll3may be rotated. In practice, the center.

pin 354 being drawn to the right in Fig. 5, the control bar is placed inposition as shown, so that its ends rest on the flat faces 362 and itssides against the screws 363, 364, after which the center pin 358 isreleased by the operator and is forced by its spring into engagementwith the socket 361 at the end of the bar. Each end of the bar is thusengaged by a three-point bearing and is held accu-.

rately in position. The clamping screws 355, 356 may e set tight to holdthe center ins in position. Ordinarily, the pressure 0 the spring-357 issuficient tocause the center pins to grip the control bar and hold :itaccurately in position without tightening the clamping screw 356. The.holding mecha 80 nismior the control bar ifs'capable \of an exceedinglyfine adjustment without distort- 'ing the control bar. The swingingarm301 which carries the dressing tool 300, is forme at its end with abearing, 369in which a thrust pin 368 -is arranged so that'the end ofthe thrust pin may project beyond the arm' and be brought against therear side of the 'control bar'359, as shown in Fig. 4. The arm is ofsuch length that it can be swung over or past the control bar, and, topermit this, the pin 368 must be partially with drawn so that itsprojecting end is substantially flush with the end of the arm. The pinis provided with a knurled head 370 which may be grasped by the operatorfor this purpose. The bearing for this thrust.

pin is split, as shown in Fig. 2, and a clamp ing screw 371 may be usedto draw the portions of the bearln together to clamp the thrust pin ineither 1ts advanced or retracted position. When the operator desires todress the grinding wheel, the arm 301 is moved from the position shownin Fig. 3 forwardly and downwardly, and the thrust pin 368 is retractedto permit the arm to pass the control bar 359. Thereafter the operatorforces the thrust pin downwardly so that its end engages the rear sideof the 'control bar, as

showninFigure 4. When in this position the counterweight 309 presses thethrust pin to be reciprocated, whereby the dressing tool traverses theface of the grinding wheel. The control bar corresponds to the shape ofthe finished work so th t the wheel is dressed to impartthat shape t anew piece of work. For example, in Fi s. 13 to 16 inclusive, I haveillustrated di erent pieces of work, and the control bars for dressingthe wheels, by which these pieces of work are finished, correspond tothe pieces as illustrated.- Where the grinding wheel consists of severalsections WhlCll vary in diameter, as, for example, in Figure 14, thereare shoulders between the several sections, and the thrust pin on thedressing toolar'm could ,not slide back and forth on the shoulderedcontrol bar. I

ures 5 and 6, I have shown the control bar 368 against the control b r'359. The opv low as being provided with the three different diametersa, Z) and '0, separated by the shoulders d and e. In the smaller section0 and in. the intermediate section b, I introduce ins 372, 373, whichare semi-cylindrical. he end of each pin is flush with the nextsectionof a larger diameter, but it is also provided with inclined faces374, 374, by which the end of the thrust pin may be guided from the forexample, to t e next section b for example, and thence to the section a.To aceriphery of one section c 'compl'ish this result, assuming that thethrust pin. 368 is moving to the left in Figure 5,.1t continues thismovementuntil by hand, rotates the control bar about its axis thrust;pin and thus ,th rust 'it rear-wardlyifar enough until itv can rideonthesections of thecontrol bar. The thrust pin then continues-itsmovement to the left untilit engages the shoulder d, Iwhereupon theeperator againrocks the, control bar to bring the pin 37 3 under thethrust'pinand again swing the thrust pin rearwardly farenough until itcan ride on the section ,a. When the thrust pin is moving in theoppositedirection or to the right, it may drop oil" of theshoulder tothe nex-t diametrically smaller section without doing any damage.It'will be remembered that thedressing tool bar 53 is moved by fluidpressure from the pump, but, inasmuch as the relief valve mechanismpreviously described is included in the hydraulic system, the thrustpint-368 may engageone of the shoulders '11 or e and be arrested with-.out damage. A very decided advantage'is thus. achieved by theemployment of a yieldingl'mechanism for operating the dressing tooHaving said invention and described a way, ofmaking and using the same,although without attempting to set forth all of the forms in which-itmay be made or all of its modes of use, what I claim is:

- 1. A grinding machine comprising a bed,

a grinding wheel, a bar journaled in the bedvparallel with the axis-ofthe grinding wheel, a dressing ool'carrier hung on said bar. and havingan inoperative position above said wheel, said carrier being movableforwardly and downwardly about the axis of said bar from saidinoperative position to bring the dressing tool into engagement withsaid-wheel, and means for moving said tool carrier lengthwise of theaxis of said bar.

2. A grinding machine comprising a bed, a grinding wheel, an arm pivotedat one end to swing about an axis substantially parallel to the axis ofthe grinding wheel, said arm having adjacent its other end means forbolding a dressing tool, means for moving-said tool carrier lengthwiseof its axis, and a template engageable by the tool-holding end of saidarm, said template extending parallel to said axis and held againstlongitudinal movement along which said arm may slideior controllin'g thepivotal movement of said arm.

' 3. A grinding machine comprising a bed, a grinding wheel, an armpivoted at one end to swing about an axis substantially parallel to theaxis of the grinding wheel, said arm having adjacent its other end meansfor holding a dressing tool, a template engageabl by the tool holdingend of said arm, said plate being arranged parallel tg said. acontrolling the pivotal movement 0 lengthwise of its axis, a templatefor-controleffecting a relative movement of said wheel and template inlines transverse to the, axis thus described the nature of mytoward andfrom said wheel, whereby the'acbe engaged, when swung into downward ac-9. A grinding machine comprising a bed, a

temis for saidlcairrir 'with'saidworlz carrier,"-and-=means [4,, Agrinding maf h'ne .v r m i i e a grinding. wheel, a pivoted dressingtool carrier movable about an, axis subst-a tially parallel to the axisof the-grindi wheel to present a tool against. the periphery/of saidwheel, means for moving said tool carrier ling thepivotal movement ofsaid tool carrier and hence the distance of the tool from the axis ofthe wheel, and mechanism for of said wheel, whereby thetemplate-controlled distance between the tool-and theaxis of the wheelmay be modified. r 5.'A grindingmachine comprising a bed,

a grindin wheel, a pivoted dressing tool carrier mova ble about an axissubstantially parallel to the axis of the grinding wheel to pre sent atool against the periphery of the wheel, means for moving vsaid toolcarrier lengthwise .of its axis, a template for controlling the pivotalmovement of said tool carrierand hence the distance between the tool andthe axis of the wheel, and manually-operated feed mechanism for feedingsaid template tion of the template may be modified withoutalteringitsshape. Y

6. Agrinding machinecomprising a bed, a grinding wheel thereon, adressing. tool carrier pivoted to the bed, counterbalancing weightsconnected to said tool carrier for holdingit normally in a raisedinactive position, and mechanism'normally .clear of said.

tdol carrier with which said tool carrier may i tive position,'forfeeding a tool carried there-- by to the grinding wheel.

-7. A grindi g machme comprising a bed, a grinding whe'el thereon, awork carrier, a dressing tool' carrier pivoted to the bed and swingabletopresent a dressing tool against the periphery of said wheel, and meansfor engaging the free end of said tool carrier with said work carrier tohold 'said tool in operative position against said wheel.

' 8. A grinding machine comprising a bed, a

,grinding wheel thereon, a dressing tool car rier pivoted to the bed, 'awork carrier pivoted to the bed and adjustable toward and 0 from saidwheel, and means for guiding the tool carrier comprising means forengaging the tool carrier with said work carrler.

grindingwheel thereon, a dressing tool carrier pivoted to the bed, awork carrier plvot ed to; the bed'and adjustable toward and from saidwheel, means forguiding the tool carrier comprising means for'engagingthetool sition out of engagement with said template, a

and means for causing relative movement between the tool carrler andtemplate longl- .tudinally of said axis.

11. A grinding machine comprising a bed, a gr nding wheel thereon, adressing tool carsaid control bar or template and for sliding I alongsaid control bar or template.

17. A grinding machine comprising a bed, a grinding wheel supportedthereon, a relatively stationary control bar or template ,cx-

tending across the face of said Wheel, an arm rier pivoted to the bedfor support and torn pivoted to said bed so that its free end maymovement toward and from said grinding wheel, a template extendingparallel to the pivot axis. of said carrier. means fordetachabliengaging said carrier with said template, a carrier pivoted tosaid bed on an axis parallel tothat of said tool carrier andindependently ofsaid tool carrier, support for carrier pivoted to thebed. for support and for movement toward and from said rindingwheel, atemplate extending parallel to the pivot axis of said carrier, means forde-'.

tacha-blv engaging said carrier with said template. meansfor-reciprocating said tool.-

carrier endwise of said template, a carrier movablv'supported bv .saidbed, independently of said tool carrier support for carrving saidtemplate. and feed mechanism for said template carrier.

13. A grinding machine compr sing a bed. a grinding wheel. a workcarrier pivoted to move toward and from the grinding wheel.

ing the tool carrier past said shoulders. said bar being movable toengage one of said faces with said tool carrier when the latter is inengagement with the adjacent shoulder.

be engaged with and disengaged from said control bar or template, and adressing tool fixed in said arm for engagement with said face of saidwheel.

18. A grinding machine comprising a bed, a grinding wheel supportedthereon, a relatively stationary control bar or template extendingacross the face of said wheel, an arm pivoted to said bed so that itsfree end may be engaged with and disengaged from said control bar ortemplate, a dressing tool fixed in said arm for engagement with saidface of "said Wheel, and means for moving said arm lengthwise'of itspivotal axis.

19. In a grinding machine, a shouldered grinding wheel, a dressing toolcarrier movable across the faces-of said wheel and toward and from thesame, a shouldered control bar along which sa1d carrler 1s movable,yielding means for moving sa1d carrier along sa1d a dressing tool, atemplate engageable by the 1.

tool-holding end of said arm and arranged parailel to said axis forcontrolling the pivotal {movement of said arm, and means for movingrelatively sto said said arm longitudinally template and said wheel.

In testimony whereof I have afiixed my signature. WILLIAM LE ROY BRYANT.

15. In a grinding machine, 1 a grinding wheel, a movable dressing toel-carrier. and

' a revolvable shouldered control bar or template. with which .saidcarrier. may be engaged and along which it may be moved, said'

